In multicell radio communication systems the technique of frequency re-use has been employed to improve transmission efficiency. For example, in a system having inbound and outbound radio communication capability, a technique is described in U.S. Pat. No. 4,670,906, entitled "DATA COMMUNICATION SYSTEM TRANSMITTER SELECTION METHOD AND APPARATUS", to Thro, and assigned to the assignee hereof, which selects a transmitter to transmit a message to a portable radio transceiver based on a received signal strength indication (RSSI) measurement of an inbound signal transmitted from the portable radio transceiver to a central controller of the radio communication system. While this technique works quite well, it has several limitations, incluring errors due to radio frequency (RF) signal fading during the RSSI measurement, lack of support of multiple channels, and unsuitability for use in a one way, outbound system. Another technique, used in a multicell, multichannel system, involves a predetermined assignment of each of several differing outbound channels (for example, seven) to each cell in a manner that allows simultaneous transmission from all cells. This technique works well when all cells are large enough that interchannel interference (most especially, adjacent channel interference) does not degrade system performance and message traffic distribution is substantially uniform. However, this technique is less successful when cells of varying size, especially small cells, are needed to provide sufficient capacity for a one-way way (outbound only) or a two way (inbound and outbound) radio communication system, and does not adapt well to non-uniform distribution of traffic.
Thus, what is needed is an improved technique for scheduling message traffic in a multicell radio communication system having heterogeneous cells and non-uniform distribution of message traffic.